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btrfs: teach __process_pages_contig about PAGE_LOCK operation

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Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ changes to the helper separated from the following patch ]
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Liu Bo 2017-02-10 16:41:05 +01:00 committed by David Sterba
parent 873695b301
commit da2c7009f6
2 changed files with 44 additions and 7 deletions
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48
fs/btrfs/extent_io.c
View File

@ -1554,6 +1554,11 @@ out:
return found;
}
static int __process_pages_contig(struct address_space *mapping,
struct page *locked_page,
pgoff_t start_index, pgoff_t end_index,
unsigned long page_ops, pgoff_t *index_ret);
static noinline void __unlock_for_delalloc(struct inode *inode,
struct page *locked_page,
u64 start, u64 end)
@ -1731,17 +1736,24 @@ out_failed:
return found;
}
static void __process_pages_contig(struct address_space *mapping,
struct page *locked_page,
pgoff_t start_index, pgoff_t end_index,
unsigned long page_ops)
static int __process_pages_contig(struct address_space *mapping,
struct page *locked_page,
pgoff_t start_index, pgoff_t end_index,
unsigned long page_ops, pgoff_t *index_ret)
{
unsigned long nr_pages = end_index - start_index + 1;
unsigned long pages_locked = 0;
pgoff_t index = start_index;
struct page *pages[16];
unsigned ret;
int err = 0;
int i;
if (page_ops & PAGE_LOCK) {
ASSERT(page_ops == PAGE_LOCK);
ASSERT(index_ret && *index_ret == start_index);
}
if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0)
mapping_set_error(mapping, -EIO);
@ -1749,13 +1761,22 @@ static void __process_pages_contig(struct address_space *mapping,
ret = find_get_pages_contig(mapping, index,
min_t(unsigned long,
nr_pages, ARRAY_SIZE(pages)), pages);
for (i = 0; i < ret; i++) {
if (ret == 0) {
/*
* Only if we're going to lock these pages,
* can we find nothing at @index.
*/
ASSERT(page_ops & PAGE_LOCK);
return ret;
}
for (i = 0; i < ret; i++) {
if (page_ops & PAGE_SET_PRIVATE2)
SetPagePrivate2(pages[i]);
if (pages[i] == locked_page) {
put_page(pages[i]);
pages_locked++;
continue;
}
if (page_ops & PAGE_CLEAR_DIRTY)
@ -1768,12 +1789,27 @@ static void __process_pages_contig(struct address_space *mapping,
end_page_writeback(pages[i]);
if (page_ops & PAGE_UNLOCK)
unlock_page(pages[i]);
if (page_ops & PAGE_LOCK) {
lock_page(pages[i]);
if (!PageDirty(pages[i]) ||
pages[i]->mapping != mapping) {
unlock_page(pages[i]);
put_page(pages[i]);
err = -EAGAIN;
goto out;
}
}
put_page(pages[i]);
pages_locked++;
}
nr_pages -= ret;
index += ret;
cond_resched();
}
out:
if (err && index_ret)
*index_ret = start_index + pages_locked - 1;
return err;
}
void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
@ -1786,7 +1822,7 @@ void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
__process_pages_contig(inode->i_mapping, locked_page,
start >> PAGE_SHIFT, end >> PAGE_SHIFT,
page_ops);
page_ops, NULL);
}
/*

3
fs/btrfs/extent_io.h
View File

@ -45,13 +45,14 @@
#define EXTENT_BUFFER_IN_TREE 10
#define EXTENT_BUFFER_WRITE_ERR 11 /* write IO error */
/* these are flags for extent_clear_unlock_delalloc */
/* these are flags for __process_pages_contig */
#define PAGE_UNLOCK (1 << 0)
#define PAGE_CLEAR_DIRTY (1 << 1)
#define PAGE_SET_WRITEBACK (1 << 2)
#define PAGE_END_WRITEBACK (1 << 3)
#define PAGE_SET_PRIVATE2 (1 << 4)
#define PAGE_SET_ERROR (1 << 5)
#define PAGE_LOCK (1 << 6)
/*
* page->private values. Every page that is controlled by the extent